Method for transferring a device identifier block on a second communication link separated from the BLUETOOTH link

ABSTRACT

Method for communicating information between a first device comprising means for communicating through a BLUETOOTH link and at least one second device also comprising means for communicating through a BLUETOOTH link. A connection link separated from the BLUETOOTH link is established between said first device and said at least one second device. A device identifier block includes data required for establishing and maintaining a BLUETOOTH link communication between said first device and a second device. The device identifier block is transferred through the connection link separated from the BLUETOOTH link.

TECHNICAL FIELD

The invention relates to a method and a device for communicatinginformation between a first device comprising means for communicatingthrough a BLUETOOTH link and at least one second device also comprisingmeans for communicating through a BLUETOOTH link.

BACKGROUND OF THE INVENTION

BLUETOOTH wireless technology is a de facto standard, as well as aspecification for small-form factor, low-cost, short-range radio linksbetween mobile PCs, mobile phones and other portable devices. When twoBLUETOOTH devices are about to communicate with each other a connectionmust be set up. One device, the initial master, must set up theconnection using a specific BLUETOOTH device address of the otherdevice.

The BLUETOOTH base-band supports link level authentication. Whenauthentication is enabled a PIN (Personal Identification Number) codemust be entered on both devices wanting to communicate before aconnection (link) can be established. The same PIN code is entered onboth devices. The PIN code is only valid between the two devices activeat the moment. A device can use different PIN codes for differentdevices it wants to communicate with. Once authentication has beenperformed the devices may choose to save a link key so that the PIN codedoes not have to be entered each time a connection is set up.

The BLUETOOTH base-band supports encryption. To enable encryption a PINcode must be entered on both devices wanting to communicate (sameprocess as for authentication). The PIN code is used to create the keyfor the encryption.

If a device has authentication turned off, any device can connect tothis device given that its BLUETOOTH device address is known. It ispossible to “snoop” the BLUETOOTH device address by listening to itscommunication with other devices.

A BLUETOOTH device normally keeps the following information stored:

-   -   BLUETOOTH device address (48-bit unique number identifying the        device).    -   Other BLUETOOTH device specific information (e.g. name, class of        device, clock offset, page scan mode).    -   PIN code to be used when connecting to this device.    -   The services it supports (e.g. LAN access profile, Serial port        profile, etc.    -   Proprietary information. Information that is specific to a        certain vendor.

The information in the list above is from now on called the DeviceIdentifier Block, the DIB for short. All or part of the information inthe DIB is needed to be able to quickly and securely establish aBLUETOOTH link with a remote device.

Usually the BLUETOOTH device address is found by doing an INQUIRY. TheINQUIRY procedure is a search procedure; it will return all theBLUETOOTH device addresses of all devices that are in the vicinity. Fora device to respond to an INQUIRY it has to be in INQUIRY_SCAN mode.This makes it visible to all devices performing INQUIRY. When an INQUIRYhas been made the user usually is prompted with a list of devices tochoose from. Once a device has been chosen, its BLUETOOTH device addresscan be saved for future connections.

An INQUIRY procedure usually takes 10 seconds. If the names of theremote devices are desired (usually the case when users are requested toselect from a list) a name request for each BLUETOOTH device addressmust be performed. This procedure will take 2.57 seconds in average foreach device. Traditionally, in BLUETOOTH, most of the informationcontained in the DIB, is transferred from one device to another usingthe INQUIRY procedure.

Not all devices have user interface to enable the user to select theappropriate device after an INQUIRY (a search), which may cause problemswhere several devices are present. In some scenarios, e.g. for securityreasons, a device cannot be in INQUIRY_SCAN since it might not besuitable for it to be visible to other devices performing INQUIRY. Itshould be noted that a BLUETOOTH device in INQUIRY_SCAN mode willrespond to INQUIRY from all devices.

In scenarios where a device often changes the device it communicateswith the INQUIRY procedure is to long to be suitable every time a changeis to be performed. In other scenarios where none of the devicescommunicating have user interface to enter a PIN code authentication andencryption cannot be used.

In scenarios where it is absolutely critical that you are communicatingwith the correct device the search and select procedure using INQUIRYand name request is not secure enough.

SUMMARY OF THE INVENTION

An object of the present invention is to overcome the drawbacks and theproblems mentioned above. In accordance with the invention a secondcommunication link is established between a first BLUETOOTH device andat least one second BLUETOOTH device. In the second communication linkcommunication media other than BLUETOOTH is used to perform anout-of-band transfer of at least one DIB.

What to do with a received DIB may vary depending on the application. Infact, in some scenarios multiple DIBs may be transferred from one deviceto another. In this case the DIBs do not contain information about thedevice they came from, instead they might describe other devices used inthat scenario.

In accordance with the invention different media can be used fortransferring a DIB. It is for instance possible to use wired, optical orinductive communication media. Also a removable storage media can beused. In either case at least the following events can trigger thetransfer of DIBs between two devices. Connectors of the devices toucheach other or their transceivers come in range. As an alternative theuser presses a button.

In accordance with different embodiments of the invention differentadvantages will be obtained. Devices using the present invention do nothave to be in INQUIRY_SCAN to be discovered; they can be discoveredusing out-of-band transfer of their DIB instead. BLUETOOTH link-levelauthentication and encryption can be used without having to enter a PINcode. The PIN code is transferred in the out-of-band transfer of theDIB.

No user interface is needed to bond with another BLUETOOTH device.Traditionally bonding involves, searching, selecting and entering a PINcode. With an out-of-band transfer of DIBs this procedure can be donequickly and in one step.

A user can quickly change the device he is communicating with by simplyreceiving the new device's DIB. Traditionally this would have involvedsearching and selecting or at least selecting from a list from aprevious search. A user/device can be absolutely sure that he/it iscommunicating with the correct device.

The DIB contains device specific information, such as BLUETOOTH deviceaddress, class of device, clock offset, etc. In addition it containsservice specific information, more precisely information about whichservices the device offers. Examples of such services (but not limitedto) can be headsets, LAN access means, speaker and light-switches. Adevice may support more than one service. By including serviceinformation in the DIB a multi-function receiving device is capable ofusing the received information in an appropriate way. E.g. a musicstereo device has the ability to connect to both a headset and amicrophone. Using out-of-band transfer the DIB of the headset and themicrophone are transferred to the stereo. So from now on, since thestereo can see in the DIB that one DIB belongs to a headset and theother belongs to a microphone, it knows which BLUETOOTH device addressto use when connecting to the headset or the microphone, respectively.

In some scenarios it might be suitable to encrypt the DIB beforetransferring it to another device. A PIN code or a password will berequired to decrypt the DIB. Since the transfer of DIBs is designed tooperate on many different communication media the DIB transfer protocolis different for different media.

However, common to all DIB transfer protocols is that they alwayssupport a service such as the transfer of a DIB. Furthermore, if thetransfer of the DIB fails, at least the receiving device must be able todetect that the transfer has failed.

Further advantages and special features of the invention appear in thefollowing description, drawings, and dependent patent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a basic embodiment of theinvention,

FIG. 2 schematically shows a first embodiment of the invention,

FIG. 3 schematically shows a second embodiment of the invention,

FIG. 4 schematically shows a third embodiment of the invention,

FIG. 5 schematically shows a fourth embodiment of the invention,

FIG. 6 schematically shows a fifth embodiment of the invention and

FIG. 7 schematically shows a sixth embodiment of the invention.

DETAILED DESCRIPTION

The basic embodiment of the invention shown in FIG. 1 comprises a firstdevice 10 and a second device 11. The first device 10 comprises an inputoutput device 12 and a control unit 13. The input output device 12 caninclude a keyboard or a push button or similar means. In someembodiments it is not necessary to provide an input output device 12 atall.

The first device also comprises a first communication means 14. Thesecond device 11 comprises a service unit 15 and a second communicationmeans 16. First and second communication means are provided to utilise acommon communication media 18. First and second devices 10, 11 comprisea conventional BLUETOOTH communication means 17.

In accordance with the invention first and second communication means14, 16 are used to establish a connection link through saidcommunication media 18 separated from a BLUETOOTH link that can beestablished between the BLUETOOTH communication means 17. The connectionlink is used to transfer any identifier data required for establishingand maintaining the BLUETOOTH link communication between the firstdevice 10 and the second device 11. Said identifier data is collected ina device identifier block, DIB.

The communication media 18 can be a wired communication media includingRS232 (UART), SPI, I2C and Ethernet. In all embodiments using a wiredcommunication media there is normally required a common connector onboth devices exchanging DIBs.

An example of a wired communication media is shown in FIG. 2 where aRS232 connector is used. The connector comprises three terminals, areceive data (RX) terminal 19, a transmit data (TX) terminal 20 and aground (GND) terminal 21. A connector comprising all of the terminals isconnected to a UART (Universal Asynchronous Receiver/Transmitter). TheUART supports an invent named Oncableinserted that occurs when twoterminals touch.

In FIG. 2 one connector comprising a receive data terminal 19, atransmit data terminal 20 and a ground terminal 21 is provided on aremote unit 22. The remote unit 22 operates as the first device and mayoperate also as a cellular telephone. A second device 11 is providedwith a similar connector comprising a receive data terminal 19, atransmit data terminal 20 and a ground terminal 21. The second device 11is connected to a mains outlet 23 for supplying power to a service unit15 in the form of a light bulb 24.

The connectors are formed in such a way that when two connectors touch,the receive data terminal 19 of one device automatically connects to atransmit data terminal 20 of the other device and vice versa. In theembodiment shown in FIG. 2 this is accomplished by forming the receivedata terminal 19 of the first device 10 in a recess and the transmitdata terminal 20 extending from the remote unit 22. The ground terminal21 may be in alignment with a cover of the remote unit 22.

A corresponding connector is provided on the second device 11. Thereceive data terminal 19 is formed as a recess to receive the protrudingtransmit data terminal 20 of the first device 10. Correspondingly, thetransmit data terminal 20 of the second device 11 protrudes and isformed to be received in the corresponding receive data terminal 19 ofthe first device 10. The ground terminal 21 of the second device isformed to engage the corresponding ground terminal 21 of the firstdevice 10 when the devices are brought together.

The embodiment shown in FIG. 2 will operate as a remote controlled lightswitch. To use the device a user moves the remote unit 22 towards thefirst device 10, so as to bring the connectors of the two devices intocontact with each other. Then an out-of-band transfer of the DIB of thesecond device occurs using the wired communication. To operate the lightthe user presses a selected button the remote unit to turn the light on.The connection between the first device and the second device isdetermined, because the remote unit 22 has received the DIB of thesecond device 11 including the device address. The remote unit 22communicates with the second device 11 through the BLUETOOTHcommunication means during normal operation.

In the embodiment shown in FIG. 3 a first device 10 comprises a remoteunit 25. The second device 11 comprises a TV set 26. The first device 10and the second device 11 are both provided with a BLUETOOTHcommunication means (not shown in the drawing). In this embodiment thereis provided an optical communication media to transfer the DIB of thesecond device 11 to the first device 10. The optical communication mediapreferably is an infrared communication media using a standardcommunication through infrared light as described by the IRDAorganisation. The DIB is transferred using normal IRDA communicationprotocols. For this purpose an infrared light receiving diode 27 isprovided on the remote unit 25 and a corresponding light emitting diodeis provided on the TV set. Normally both devices are capable oftransferring information in both directions.

In the embodiment shown in FIG. 3 the remote unit 25 operates as atraditional TV remote control, in this case communicating with the TVset using a BLUETOOTH communication means. To be able to communicatewith the TV set the remote control unit 25 must know the BLUETOOTHdevice address of the TV set 26. An out-of-band transfer of the DIB fromthe TV set to the remote unit is used, for instance after pushing aselected key on the remote unit 26 for requesting the TV set to transferthe requested DIB. Normally, an IR communication link requires the twodevices to be in site of each other, thereby avoiding communication withother devices.

Another wireless communication method is shown in FIG. 4. The firstdevice comprises a keyboard 29, and the second device comprises acomputer 30. The keyboard 29 is provided with an inductive communicationmeans 31. A corresponding second inductive communication means 32 isprovided on the computer 30. By bringing the keyboard 29 in closeproximity with the computer 30 the DIB will be transferred from thecomputer to the keyboard. Also in this wireless solution other deviceswill not interfere in the communication between the selected firstdevice 10 and second device 11.

A fourth embodiment of the invention is shown in FIG. 5. The firstdevice 10 comprises a computer 32 having means 33 for receiving aremovable storage media, such as a multimedia card, MMC, or a compactflash storage card. A memory card 34 is shown partly inserted in thecomputer 32. One or more DIBs are stored on the removable storage media.To transfer the DIB from the computer 32 to the second device comprisinga keyboard 35 the storage media 34 is removed from the first device andthen inserted into the second device. The second device reads theappropriate DIBs from the storage media.

Any of the out-of-band transfer modes described above can be used alsoin other embodiments. Consider for example a simple device, such as adata-collecting device, which is designed to communicate with a LAN viaa BLUETOOTH LAN access point. Normally, there would be a problem for afirst device to know which BLUETOOTH device address to connect to. Anout-of-band transfer of the DIB from the LAN access point to the simpledevice will solve this problem. In such a scenario a wired out-of-bandtransfer of the DIB might be most appropriate.

A user intending to connect his data-collecting device to a network viaa BLUETOOTH LAN access point moves the data-collecting device intoengagement with the LAN access point to touch a connecting means, sothat the LAN access point can transfer the DIB to the data-collectingdevice. Then it is possible for the user to connect to the network viathe BLUETOOTH LAN access point, since the data-collecting device nowknows the correct BLUETOOTH device address to connect to.

When one of said first device and said second device comprises a displayand a keyboard it is possible for a user to select which device tocommunicate with on the basis of the information given on the display.The displayed information may include device specific information suchas a chosen name for the device and also the services supported by thedevice. Such information facilitates the selection of a specific devicewhen a plurality of devices is available.

Even when all BLUETOOTH devices in a specific area lack a display theinvention will facilitate a connection between two selected devices. Byusing for instance an inductive out-of-band transfer of the DIB it willbe possible for a user of a first device to establish contact with andcommunicate with anyone of a plurality of available devices. For eachdevice the user of the first device would like to establish contact withthe devices are brought into the vicinity of each other to transfer therequired DIB between the devices. Then it is possible to establish astandard BLUETOOTH connection between the first device and the selectedsecond device.

Another optical type connection link is shown in FIG. 6. The seconddevice 11 is formed as a cellular telephone and comprises a bar codereader 41. The corresponding first device 10 is formed as a computer andis provided with a bar code 42 carrying any required and appropriatedevice identifier data. A connection link between the first and thesecond device is established when the bar code reader is moved into thevicinity of the bar code, so as to be able to read the bar code. Afterreading the bar code and extracting the required information therefromthe BLUETOOTH link communication between said first device and a seconddevice could be established and maintained.

A fifth embodiment of the invention as shown in FIG. 7 relates to a shopwith a large number of cash registers. Shoppers are able to pay theirmerchandise using a WAP browser in their cellular telephones. A problemin such an embodiment is to ensure that the shopper will pay the correctbill, by communicating with the correct cash register. A search andselect procedure may take too much time and still it may not be obviousto select the correct cash register to connect to.

As shown in FIG. 7 a first cash register 36 is arranged at a first line37. A first user 38, a second user 39 and a plurality of other users arelined up in the first line 37. A second line 40 and a plurality offurther lines are arranged in a similar manner as the first line.

When the first user 38 is prepared to pay his bill at the first cashregister 36 using the WAP browser in a cellular telephone the userpasses the telephone in front of the cash register 36. The DIB of thecash register 36 is then transferred to the cellular telephone, forinstance using an inductive communication media 18. After the transferof the DIB the cellular telephone can securely connect to the correctcash register, because the correct BLUETOOTH device address to use isknown. Other devices in other lines will not effect the communicationbetween the cash register 36 and the cellular telephone of the firstuser 38.

In either type of connection link provided in accordance with thepresent invention a PIN code can be a part of the informationtransferred between the first device and the second device. In this waythe transfer of secure information to any undesired device can beavoided. After transferring the PIN code a BLUETOOTH authentication andencryption process can be initiated and completed.

According to the invention it is possible also to transfer multipleDIBs. An access point is provided to cover a plurality of BLUETOOTHdevices. The DIB of each of the devices associated to the access pointis transferred to the access point in advance. By using a communicationmedia 18 other than BLUETOOTH a user may access any selected DIBpreviously transferred to the access point. In a practical embodiment auser removes a storage card from a portable device and inserts it in theaccess point. The access point may be provided with a keyboard and adisplay to allow the user to select a specific device or a plurality ofdevices associated to the access point. Information corresponding toeach of the DIB of the selected devices is transferred to the storagecard. The storage card can then be removed from the access point andagain inserted in the portable device. A suitable software in theportable device reads the DIB information in the storage card andenables the user to connect to any selected device.

1. A method for communicating information between a first devicecomprising means for communicating through a BLUETOOTH link and at leastone second device also comprising means for communicating through aBLUETOOTH link, the method including the steps of: establishing aconnection link separated from the BLUETOOTH link between said firstdevice and said at least one second device: transferring, in a deviceidentifier block, data required for establishing and maintaining aBLUETOOTH link communication between said first device and a seconddevice: storing a device identifier block of at least one first devicein a removable storage media; moving said removable storage media to asecond device; reading said device identifier block in the seconddevice; and establishing the connection link when the device identifierblock has been read.
 2. The method as claimed in claim 1, furtherincluding the steps of: providing a wired link as the connection linkseparated from the BLUETOOTH link; and establishing the connection linkwhen a connector of said first device engages a corresponding connectorof said second device.
 3. The method as claimed in claim 1, furtherincluding the steps of: providing an inductive link as the connectionlink separated from the BLUETOOTH link; and establishing the connectionlink when a connecting means of said first device is in the vicinity ofa corresponding connecting means of said second device.
 4. The method asclaimed in claim 1, further including the steps of: providing an opticallink as the connection link separated from the BLUETOOTH link; andestablishing the connection link when an optical communicating means ofsaid first device is in sight of a corresponding optical communicatingmeans of said second device.
 5. The method as claimed in claim 1,further including the steps of: providing a bar code exhibiting datacorresponding to the device identifier block of a first device on thefirst device; providing a bar code reader in said second device; andestablishing the connection link when the bar code reader is able toread the bar code.
 6. A device for communicating information between afirst device comprising BLUETOOTH communication means and at least onesecond device also comprising BLUETOOTH communication means, comprising:a first communication means at said first device, said firstcommunication means separated and different from the BLUETOOTHcommunication means; and a second communication means at said seconddevice separated and different from the BLUETOOTH communication means,wherein said first communication means and said second communicationmeans are adapted to communicate over a communication media differentfrom BLUETOOTH and to transfer identifier data required for establishingand maintaining a BLUETOOTH link communication between said first deviceand said second device, and wherein said first device and said seconddevice comprise means for receiving a removable storage media, andwherein said first communication means and said second communicationmeans are adapted to read/write a device identifier block stored in theremovable storage media.
 7. The device as claimed in claim 6, whereinsaid first communication means and said second communication meanscomprise terminals for a physical connection between said first deviceand said second device.
 8. The device as claimed in claim 7, whereinsaid terminals include a receive data terminal, a transmit dataterminal, and a ground terminal, the receive data terminal of each ofsaid first device and said second device being formed to engageexclusively with the transmit data terminal of said second device andsaid first device, respectively.
 9. The device as claimed in claim 6,wherein said first communication means and said second communicationmeans comprise inductive communication means.
 10. The device as claimedin claim 6, wherein said first device and said second device compriseoptical communication means operating as the communicating media. 11.The device as claimed in claim 6, wherein said first device is providedwith a bar code exhibiting data including the device identifier data,and wherein said second device comprises a bar code reader adapted toread said device identifier data.
 12. A method for communicatinginformation between a first device comprising means for communicatingthrough a BLUETOOTH link and at least one second device also comprisingmeans for communicating through a BLUETOOTH link, the method includingthe steps of: establishing a connection link separated from theBLUETOOTH link between said first device and said at least one seconddevice; transferring, in a device identifier block, data required forestablishing and maintaining a BLUETOOTH link communication between saidfirst device and a second device; providing a bar code exhibiting datacorresponding to the device identifier block of a first device on thefirst device; providing a bar code reader in said second device; andestablishing the connection link when the bar code reader is able toread the bar code.
 13. A device for communicating information between afirst device comprising BLUETOOTH communication means and at least onesecond device also comprising BLUETOOTH communication means, comprising:a first communication means at said first device, said firstcommunication means separated and different from the BLUETOOTHcommunication means; and a second communication means at said seconddevice separated and different from the BLUETOOTH communication means,wherein said first communication means and said second communicationmeans are adapted to communicate over a communication media differentfrom BLUETOOTH and to transfer identifier data required for establishingand maintaining a BLUETOOTH link communication between said first deviceand said second device, and wherein said first device is provided with abar code exhibiting data including the device identifier data, andwherein said second device comprises a bar code reader adapted to readsaid device identifier data.